The guaiac tree is one of the widespread yoke leaf plants (zygophyllaceae) in the tropics and subtropics and is a native of the West Indian islands as well as of the countries on the north coast of South America. The wood of the guaiac tree has been used for a long time as a traditional medicine by indian tribes of Middle and South-America. The wood reached Spain at the beginning of the 16th century and spread from where to the rest of Europe where it was initially used as “Lignum sanctum” (holy wood) especially for syphilis. In the course of time guaiac wood was also administered for the treatment of numerous other diseases above all for rheumatic diseases, arthritis, asthma, tuberculosis and malaria. Applications for the treatment of smallpox gave the tropical wood among others the popular name “pockwood”. Ramos et al. (Arch. Med. Res. 1992; 23, 59-64) additionally describe a pronounced hypoglycaemic effect for an extract from Guajacum coulteri. 
Guaiac wood consisting of the heartwood and the sapwood contains guaiac resin as the main active ingredient which is stored in the wood in zones resembling irregular annual rings. The heartwood contains up to 25% resin whereas only 2 to 3% resin is present in the sapwood. This resin is composed of various colophonic acids of the furoguaiacin type (α+β guaiaconic acid) and lignan type (guaiaretic acid and guaiacinic acid) as well as the phenol guaiacol. Other active ingredients of guaiac wood include essential oils (guaiac wood oil) which is mainly composed of the sesquiterpene alcohol guaiol, alkaloids and triterpene saponins with the aglycone oleanolic acid.
Whereas the ingredients of guaiac resin have a diuretic and diaphoretic effect, the fungicidal action of an extract of guaiac wood is due to the saponins contained in the wood. Guaiac oil has anti-inflammatory, antiseptic and wound healing promoting properties. In the food industry guaiac resin is used as an antioxidant to preserve above all animal fats. Since, guaiac resin is also a sensitive chemical reagent to oxidases and peroxidases, it is additionally used to detect blood in urine and faeces (haemoccult test). This detection of an occult blood is based on the oxidation of α-guaiaconic acid to the quinoid guaiac blue (furoguaiacin blue).
Although an application of guaiac wood or of guaiac resin has been described in connection with numerous medical indications but in particular as part of a homeopathic treatment of rheumatic diseases, there are no studies whatsoever in the literature on the effect of such an extract in humans which would satisfy today's standards or could be rated as relevant. In particular there are no indications whatsoever in the literature for an application of an extract from guaiac wood to treat inflammations of the skin.
GB 2 067 899 A describes cosmetic compositions for treating the skin and/or hair which contain a powder of plant origin obtained from extraction residues of various plants. Guaiac wood (Lignum vitae) is mentioned as one of the plants from which such an extraction residue can be obtained by extracting therapeutically and/or cosmetically active substances with water or organic solvents.
EP 0 265 662 A2 discloses pharmaceutical agents which are pressed together from components of various plants cut up into small pieces and can be used to treat a diversity of diseases such as for example cardiovascular diseases, angina pectoris, psoriasis, allergic dermatitis, chronic infections, bronchial asthma and hepatitis. In this connection a composition is described among others which also contains guaiac wood (Guaiacum officinale) in a comminuted form in addition to a number of other components.
JP 10158126 A discloses a hair cosmetic which in addition to at least one antimicrobial compound, contains one or more compounds selected from the group comprising lecithin, ascorbic acid, erythorbic acid, guaiac resin, nordihydro-guaiaretic acid, gallus acid, a salt of ascorbic acid, a salt of erythorbic acid and a salt of nordihydroguairetic acid.